<template>
  <div :class="classes" @mousedown.prevent>
    <div :class="[prefixCls + '-sidebar']" v-if="shortcuts.length">
      <div
        :class="[prefixCls + '-shortcut']"
        v-for="shortcut in shortcuts"
        :key="shortcut.text"
        @click="handleShortcutClick(shortcut)"
      >
        {{ shortcut.text }}
      </div>
    </div>
    <div :class="panelBodyClasses">
      <div
        :class="[prefixCls + '-content', prefixCls + '-content-left']"
        v-show="!isTime"
      >
        <div
          :class="[datePrefixCls + '-header']"
          v-show="currentView !== 'time'"
        >
          <span 
            :class="iconBtnCls('prev', '-double')" 
            @click="prevYear('left')">
            <Icon type="ios-arrow-back"></Icon>
          </span>
          <span
            v-if="leftPickerTable === 'date-table'"
            :class="iconBtnCls('prev')"
            @click="prevMonth('left')"
            v-show="currentView === 'date'">
            <Icon type="ios-arrow-back"></Icon>
          </span>
          <date-panel-label
            :date-panel-label="leftDatePanelLabel"
            :current-view="leftDatePanelView"
            :date-prefix-cls="datePrefixCls"
          ></date-panel-label>
          <span
            v-if="splitPanels || leftPickerTable !== 'date-table'"
            :class="iconBtnCls('next', '-double')"
            @click="nextYear('left')">
            <Icon type="ios-arrow-forward"></Icon>
          </span>
          <span
            v-if="splitPanels && leftPickerTable === 'date-table'"
            :class="iconBtnCls('next')"
            @click="nextMonth('left')"
            v-show="currentView === 'date'">
            <Icon type="ios-arrow-forward"></Icon>
          </span>
        </div>
        <component
          :is="leftPickerTable"
          ref="leftYearTable"
          v-if="currentView !== 'time'"
          :table-date="leftPanelDate"
          selection-mode="range"
          :disabled-date="disabledDate"
          :range-state="rangeState"
          :show-week-numbers="showWeekNumbers"
          :model-value="preSelecting.left ? [dates[0]] : dates"
          :focused-date="focusedDate"
          @on-change-range="handleChangeRange"
          @on-pick="panelPickerHandlers.left"
          @on-pick-click="handlePickClick"
        ></component>
      </div>
      <div
        :class="[prefixCls + '-content', prefixCls + '-content-right']"
        v-show="!isTime"
      >
        <div
          :class="[datePrefixCls + '-header']"
          v-show="currentView !== 'time'"
        >
          <span
            v-if="splitPanels || rightPickerTable !== 'date-table'"
            :class="iconBtnCls('prev', '-double')"
            @click="prevYear('right')">
            <Icon type="ios-arrow-back"></Icon> 
          </span>
          <span
            v-if="splitPanels && rightPickerTable === 'date-table'"
            :class="iconBtnCls('prev')"
            @click="prevMonth('right')"
            v-show="currentView === 'date'">
            <Icon type="ios-arrow-back"></Icon>
          </span>
          <date-panel-label
            :date-panel-label="rightDatePanelLabel"
            :current-view="rightDatePanelView"
            :date-prefix-cls="datePrefixCls"
          ></date-panel-label>
          <span
            :class="iconBtnCls('next', '-double')"
            @click="nextYear('right')">
            <Icon type="ios-arrow-forward"></Icon>
          </span>
          <span
            v-if="rightPickerTable === 'date-table'"
            :class="iconBtnCls('next')"
            @click="nextMonth('right')"
            v-show="currentView === 'date'">
            <Icon type="ios-arrow-forward"></Icon>
          </span>
        </div>
        <component
          :is="rightPickerTable"
          ref="rightYearTable"
          v-if="currentView !== 'time'"
          :table-date="rightPanelDate"
          selection-mode="range"
          :range-state="rangeState"
          :disabled-date="disabledDate"
          :show-week-numbers="showWeekNumbers"
          :model-value="preSelecting.right ? [dates[dates.length - 1]] : dates"
          :focused-date="focusedDate"
          @on-change-range="handleChangeRange"
          @on-pick="panelPickerHandlers.right"
          @on-pick-click="handlePickClick"
        ></component>
      </div>
      <div :class="[prefixCls + '-content']" v-show="isTime">
        <time-picker
          ref="timePicker"
          v-if="currentView === 'time'"
          :model-value="dates"
          :format="format"
          :time-disabled="timeDisabled"
          v-bind="timePickerOptions"
          @on-pick="handleRangePick"
          @on-pick-click="handlePickClick"
          @on-pick-clear="handlePickClear"
          @on-pick-success="handlePickSuccess"
          @on-pick-toggle-time="handleToggleTime"
        ></time-picker>
      </div>
      <Confirm
        v-if="confirm"
        :show-time="showTime"
        :is-time="isTime"
        :time-disabled="timeDisabled"
        @on-pick-toggle-time="handleToggleTime"
        @on-pick-clear="handlePickClear"
        @on-pick-success="handlePickSuccess"
      ></Confirm>
    </div>
  </div>
</template>
<script>
import Icon from '../../../icon/icon.vue'
import DateTable from '../../base/date-table.vue'
import YearTable from '../../base/year-table.vue'
import MonthTable from '../../base/month-table.vue'
import TimePicker from '../Time/time-range.vue'
import Confirm from '../../base/confirm.vue'

import { toDate, initTimeDate, formatDateLabels } from '../../util'
import datePanelLabel from './date-panel-label.vue'

import Mixin from '../panel-mixin'
import DateMixin from './date-panel-mixin'
import Locale from '../../../../mixins/locale'

const prefixCls = 'haloe-picker-panel'
const datePrefixCls = 'haloe-date-picker'

const dateSorter = (a, b) => {
  if (!a || !b) return 0
  return a.getTime() - b.getTime()
}

export default {
  name: 'RangeDatePickerPanel',
  mixins: [Mixin, Locale, DateMixin],
  components: {
    Icon,
    DateTable,
    YearTable,
    MonthTable,
    TimePicker,
    Confirm,
    datePanelLabel,
  },
  props: {
    // more props in the mixin
    splitPanels: {
      type: Boolean,
      default: false,
    },
  },
  data() {
    const [minDate, maxDate] = this.modelValue.map(
      (date) => date || initTimeDate()
    )
    const leftPanelDate = this.startDate ? this.startDate : minDate

    return {
      prefixCls: prefixCls,
      datePrefixCls: datePrefixCls,
      dates: this.modelValue,
      rangeState: {
        from: this.modelValue[0],
        to: this.modelValue[1],
        selecting: minDate && !maxDate,
      },
      currentView: this.selectionMode || 'range',
      leftPickerTable: `${this.selectionMode}-table`,
      rightPickerTable: `${this.selectionMode}-table`,
      leftPanelDate: leftPanelDate,
      rightPanelDate: new Date(
        leftPanelDate.getFullYear(),
        leftPanelDate.getMonth() + 1,
        1
      ),
    }
  },
  computed: {
    classes() {
      return [
        `${prefixCls}-body-wrapper`,
        `${datePrefixCls}-with-range`,
        {
          [`${prefixCls}-with-sidebar`]: this.shortcuts.length,
          [`${datePrefixCls}-with-week-numbers`]: this.showWeekNumbers,
        },
      ]
    },
    panelBodyClasses() {
      return [
        prefixCls + '-body',
        {
          [prefixCls + '-body-time']: this.showTime,
          [prefixCls + '-body-date']: !this.showTime,
        },
      ]
    },
    leftDatePanelLabel() {
      return this.panelLabelConfig('left')
    },
    rightDatePanelLabel() {
      return this.panelLabelConfig('right')
    },
    leftDatePanelView() {
      return this.leftPickerTable.split('-').shift()
    },
    rightDatePanelView() {
      return this.rightPickerTable.split('-').shift()
    },
    timeDisabled() {
      return !(this.dates[0] && this.dates[1])
    },
    preSelecting() {
      const tableType = `${this.currentView}-table`

      return {
        left: this.leftPickerTable !== tableType,
        right: this.rightPickerTable !== tableType,
      }
    },
    panelPickerHandlers() {
      return {
        left: this.preSelecting.left
          ? this.handlePreSelection.bind(this, 'left')
          : this.handleRangePick,
        right: this.preSelecting.right
          ? this.handlePreSelection.bind(this, 'right')
          : this.handleRangePick,
      }
    },
  },
  watch: {
    modelValue(newVal) {
      const minDate = newVal[0] ? toDate(newVal[0]) : null
      const maxDate = newVal[1] ? toDate(newVal[1]) : null
      this.dates = [minDate, maxDate].sort(dateSorter)

      this.rangeState = {
        from: this.dates[0],
        to: this.dates[1],
        selecting: false,
      }

      // set panels positioning
      this.setPanelDates(this.startDate || this.dates[0] || new Date())
    },
    currentView(currentView) {
      const leftMonth = this.leftPanelDate.getMonth()
      const rightMonth = this.rightPanelDate.getMonth()
      const isSameYear =
        this.leftPanelDate.getFullYear() === this.rightPanelDate.getFullYear()

      if (currentView === 'date' && isSameYear && leftMonth === rightMonth) {
        this.changePanelDate('right', 'Month', 1)
      }
      if (currentView === 'month' && isSameYear) {
        this.changePanelDate('right', 'FullYear', 1)
      }
      if (currentView === 'year' && isSameYear) {
        this.changePanelDate('right', 'FullYear', 10)
      }
    },
    selectionMode(type) {
      this.currentView = type || 'range'
    },
    focusedDate(date) {
      this.setPanelDates(date || new Date())
    },
  },
  methods: {
    reset() {
      this.currentView = this.selectionMode
      this.leftPickerTable = `${this.currentView}-table`
      this.rightPickerTable = `${this.currentView}-table`
    },
    setPanelDates(leftPanelDate) {
      this.leftPanelDate = leftPanelDate
      const rightPanelDate = new Date(
        leftPanelDate.getFullYear(),
        leftPanelDate.getMonth() + 1,
        1
      )
      const splitRightPanelDate = this.dates[1]
        ? this.dates[1].getTime()
        : this.dates[1]
      this.rightPanelDate = this.splitPanels
        ? new Date(Math.max(splitRightPanelDate, rightPanelDate.getTime()))
        : rightPanelDate
    },
    panelLabelConfig(direction) {
      const locale = this.t('i.locale')
      const datePanelLabel = this.t('i.datepicker.datePanelLabel')
      const handler = (type) => {
        const fn = type == 'month' ? this.showMonthPicker : this.showYearPicker
        return () => fn(direction)
      }

      const date = this[`${direction}PanelDate`]
      const { labels, separator } = formatDateLabels(
        locale,
        datePanelLabel,
        date
      )

      return {
        separator: separator,
        labels: labels.map((obj) => ((obj.handler = handler(obj.type)), obj)),
      }
    },
    prevYear(panel) {
      const increment = this.currentView === 'year' ? -10 : -1
      this.changePanelDate(panel, 'FullYear', increment)
    },
    nextYear(panel) {
      const increment = this.currentView === 'year' ? 10 : 1
      this.changePanelDate(panel, 'FullYear', increment)
    },
    prevMonth(panel) {
      this.changePanelDate(panel, 'Month', -1)
    },
    nextMonth(panel) {
      this.changePanelDate(panel, 'Month', 1)
    },
    changePanelDate(panel, type, increment, updateOtherPanel = true) {
      const current = new Date(this[`${panel}PanelDate`])
      // fix https://github.com/view-design/ViewUI/issues/418
      // 强行把左视图日期设置为1号
      // FullYear 不能设置https://github.com/iview/iview/issues/6600
      if (type === 'FullYear')
        current[`set${type}`](current[`get${type}`]() + increment)
      else current[`set${type}`](current[`get${type}`]() + increment, 1)

      this[`${panel}PanelDate`] = current

      if (!updateOtherPanel) return

      if (this.splitPanels) {
        // change other panel if dates overlap
        const otherPanel = panel === 'left' ? 'right' : 'left'
        if (panel === 'left' && this.leftPanelDate >= this.rightPanelDate) {
          this.changePanelDate(otherPanel, type, 1)
        }
        if (panel === 'right' && this.rightPanelDate <= this.leftPanelDate) {
          this.changePanelDate(otherPanel, type, -1)
        }
      } else {
        // keep the panels together
        const otherPanel = panel === 'left' ? 'right' : 'left'
        const currentDate = this[`${otherPanel}PanelDate`]
        const temp = new Date(currentDate)

        if (type === 'Month') {
          const nextMonthLastDate = new Date(
            temp.getFullYear(),
            temp.getMonth() + increment + 1,
            0
          ).getDate()
          temp.setDate(Math.min(nextMonthLastDate, temp.getDate()))
        }

        temp[`set${type}`](temp[`get${type}`]() + increment)
        this[`${otherPanel}PanelDate`] = temp
      }
    },
    showYearPicker(panel) {
      this[`${panel}PickerTable`] = 'year-table'
    },
    showMonthPicker(panel) {
      this[`${panel}PickerTable`] = 'month-table'
    },
    handlePreSelection(panel, value) {
      this[`${panel}PanelDate`] = value
      const currentViewType = this[`${panel}PickerTable`]
      if (currentViewType === 'year-table')
        this[`${panel}PickerTable`] = 'month-table'
      else this[`${panel}PickerTable`] = `${this.currentView}-table`

      if (!this.splitPanels) {
        const otherPanel = panel === 'left' ? 'right' : 'left'
        this[`${otherPanel}PanelDate`] = value

        const increment = otherPanel === 'left' ? -1 : 1 // #3973

        this.changePanelDate(otherPanel, 'Month', increment, false)
      }
    },
    handleRangePick(val, type) {
      if (this.rangeState.selecting || this.currentView === 'time') {
        if (this.currentView === 'time') {
          this.dates = val
        } else {
          const [minDate, maxDate] = [this.rangeState.from, val].sort(
            dateSorter
          )
          this.dates = [minDate, maxDate]
          this.rangeState = {
            from: minDate,
            to: maxDate,
            selecting: false,
          }
        }
        this.handleConfirm(false, type || 'date')
      } else {
        this.rangeState = {
          from: val,
          to: null,
          selecting: true,
        }
      }
    },
    handleChangeRange(val) {
      this.rangeState.to = val
    },
  },
}
</script>
